JPS5822724Y2 - spot shot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spot shot drive device that automates the movement of a spot shot device.

To perform X-ray photography, the general method is to see the affected area before taking the image, and then take timely images while looking at the fluoroscopic image.For this purpose, the X-ray film is attached to a spot shot device, and the spot shot During imaging, it is moved from the fluoroscopy position to the imaging position within the device.

By the way, when performing X-ray photography with the spot shot device in place, it is necessary to keep the spot shot device in close contact with the patient's abdomen in order to obtain a high-quality X-ray photograph.

Therefore, this type of X-ray apparatus is equipped with a spot shot drive device for moving the spot shot device with respect to the examinee as the subject. Conventionally, the drive device is configured as shown in FIG. In Figure 1, patient 1
is a diagnostic bed 2 in which an X-ray generator 3 is installed.
A spot shot device 4 is placed on the patient's body 1, and a spot shot device 4 is provided so as to be movable forward and backward relative to the patient 1.

On the other hand, 5 is a drive unit power supply, and the output of this power supply 5 is given to a drive unit 8 consisting of an electric motor etc. through a normally open contact of an operation switch 6 and a normally closed contact of a cutoff switch 7, and from this 7 drive unit 8. Occur.

The driving force is applied to the spot shot device 4 via a power transmission mechanism 9 such as a chain transmission mechanism, for example.

When the operator closes the operation switch 6, the drive section 8 is activated, and the spot shot device 4 is moved in the direction A in the drawing.

On the other hand, the related author monitors this movement, and when the spot shot device 4 comes into close contact with the patient 4, the operation switch 6 is opened, the power supply 5 of the first drive unit 8 is cut off, and the movement of the spot shot device 4 is stopped. let

By the way, in this case, the spot shot device 4 is
Despite pressing , the movement of the spot shot device 4 in the direction A in the drawing may not be stopped due to the supervisor's carelessness or the like.

In such a situation, excessive pressure will be applied to the patient, which is dangerous.

Therefore, many devices are equipped with a contact detection control section as a safety mechanism.

This contact detection control section is provided with a contact detector 10 such as a mud switch on the front side of the spot shot device 4, and introduces a detection signal from this detector 10 into a switch cutoff circuit 11 to open the cutoff switch 7 and drive it. This is to cut off the power supply 5 of the section 8.

On the other hand, in recent years, the establishment of operational safety and automation have been carried out in parallel with X-ray equipment, and even in the moving operation of the spot shot equipment, the operator's monitoring operation has become more and more important. In order to reduce the burden, automation of the movement operation is desired.

Therefore, in the conventional device shown in FIG. 1, a contact detector 10 as a safety mechanism is used as an element for automation, and a cutoff switch is used that relies on the contact signal of the detector 10 for each operation. 7
It is conceivable to open the circuit and stop the movement of the spot shot device 4.

However, as mentioned above, the contact detector 10 is only an auxiliary means for stopping the movement as a safety mechanism, and therefore opening and closing the contact detector 10 during each operation requires mechanical pressure, wear and tear. etc., reducing the reliability of the contact detector 10.

Furthermore, in the conventional device shown in FIG. 1, the moving speed of the spot shot device 4 is always constant, so if the operating speed is increased, the impact force on the patient 1 at the time of contact increases accordingly, so it is necessary to increase the operating speed. I can't.

Therefore, the present invention was developed in view of the above-mentioned circumstances, and it detects the actual amount of movement of the Spotshot device and controls the driving force of the Spotshot device according to this amount of movement, so that the Spotshot device can An object of the present invention is to provide a spot shot drive device that automatically stops when the spot shot device is in close contact with the patient, automates the movement amount f'F- of the spot shot device, and improves safety for patients. .

Hereinafter, an embodiment of the present invention will be described with reference to the drawings in which the same parts as in FIG. 1 are denoted by the same reference numerals.

In FIG. 2, 21 is a powder clutch interposed between the drive section 8 and the transmission mechanism 9, serving as a drive torque transmission adjustment mechanism that suppresses the drive torque of the drive section 8 and transmits it to the transmission mechanism 9. This powder clutch 21 can control the transmitted torque by exciting current.

Reference numeral 22 denotes a movement amount detector that detects the movement amount of the spot shot device 4 from the rotational force of the transmission mechanism 9, etc.; 23 receives the detection output of the movement amount detector 22, and detects the powder clutch 21 according to the movement amount; This is an adjustment mechanism control circuit that generates a control signal to control the transmission torque of the motor.

That is, the movement amount detector 22 and the adjustment mechanism control circuit 23 constitute a movement detection control section.

5. The relationship between the excitation current of the powder clutch 21 and the transmitted torque is generally as shown in FIG.

Therefore, in order to obtain sufficient starting torque when starting the spot shot device 4, the powder clutch 21 is initially equipped with ■1.
Settings are made so that the excitation current flows and the transmission torque at's is obtained.

On the other hand, the control circuit 23 receives the detection signal from the movement amount detector 22, and controls the actual movement amount to change as shown in FIG. The excitation current of the powder clutch 21 is controlled.

In the above structure, when the operation switch 6 is closed, the power source 5bS is applied to the drive unit 8, and the drive unit 8 starts operating.

The drive torque generated in this drive unit 8 is transferred to the powder clutch 2.
1 to the transmission mechanism 9, but since the transmission torque in this case is initially set as shown by a in FIG. 3, the spot shot device 4 moves in the direction A in the figure with sufficient starting torque. be done.

On the other hand, the amount of movement of this spot shot device 4 is detected by a movement amount detector 22, and this detection output is introduced into a control circuit 23, and the amount of movement is controlled with respect to time, as shown in FIG. The excitation current of the powder clutch 21 is limited by the control output of the control circuit 230 so that the quantity characteristics are realized.

That is, when the movement amount of the spot shot device 4 reaches point C on the characteristic curve shown in FIG. 4, the excitation current is limited to I2 shown in FIG.
shall be.

Therefore, when the movement distance of the spot shot device 4 becomes C and it approaches the patient 1, its movement speed is greatly restricted as is clear from FIG. 4, and the spot shot device 4 and the patient 1 come into contact with each other. The moving speed and driving torque are also sufficiently safe.

Then, after T2 time has passed since the start of movement, the amount of movement becomes d,
The spot shot device 4 and the patient 1 are brought into contact with an appropriate pressure, the excitation current of the adjustment mechanism 21 is suppressed to zero by the output of the force control circuit 23, and the spot shot device 4 stops moving at that position.

By the way, the body thickness of the patient varies from person to person, and when the spot shot device 4 moves by a distance d.

The spot shot device 4 does not necessarily come into contact with the patient.

Therefore, the moving amount d is set to the maximum distance necessary for contact between the patient 1 and the spot shot device 4, and the moving speed and driving torque are sufficiently reduced for patients with large body thickness. In this state, the contact detection control unit is operated to introduce the contact signal from the contact detector 10 such as a mud switch provided on the front side of the spot shot device 4 to the cutoff circuit 11 consisting of a relay coil or the like to open the cutoff switch 7. , the power source 5 is disconnected from the drive unit 8, and the movement of the spot shot device 4 is stopped.

That is. The contact detection control unit is used for its primary function of ensuring safety.

As described above, the spot shot device 4 can be safely and reliably brought into contact with patients of all body thicknesses.

In the embodiment shown in FIG. 2, a mechanical contact detector 10 is used as the detection section of the contact detection control section as a safety mechanism, but this can be done electrically.

That is, as shown in FIG. 5, the output of the movement amount detector 22 is introduced into a differentiating circuit 24, and its time derivative is taken. 21 has already been sufficiently suppressed, the movement speed of the spot shot device 4 is sufficiently slow and the driving force is small, so there is no risk of excessive pressure being applied to the patient by the spot shot device 4.) When the output of the differentiating circuit 24 becomes less than a certain constant value, for example less than zero, the signal is introduced into the cutoff circuit 11 and the cutoff switch 7 is opened.

In other words, in this case, the contact detection control section includes the cutoff switch 7,
Cutoff circuit 11, movement amount detector 22, and differentiation circuit 24
It will be composed of.

According to this Figure 5, there are no mechanical parts, so
Safety will be even higher.

As described above, according to the present invention, a powder clutch is provided between the spot shot drive unit and the transmission mechanism, which can control the transmitted torque by an external control signal, and the actual movement amount of the spot shot device is detected. Since the torque transmitted by the powder clutch is suppressed according to the amount of movement, as the Spot Shot device approaches the patient, its movement speed and drive torque are suppressed, and eventually contact detection (or planned position detection) ) by reducing the transmission torque (or driving force) to zero, it is possible to automate the contact adjustment between the spot shot device and the patient, and to provide a spot shot drive device that can perform the contact operation reliably and safely.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a conventional spot shot drive device, FIG. 2 is a block diagram showing an embodiment of the present invention, FIGS. 3 and 4 are diagrams showing operating characteristics of the same embodiment, and FIG. The figure is a configuration diagram showing another embodiment of the present invention. 8... Drive unit, 9... Transmission mechanism, 21
. . . Powder clutch, 22 . . . Movement amount detector, 23 . . . Control circuit.

Claims (1)

[Scope of utility model registration request] It has a power supply and connects the spot shot device to the subject.
The device includes an electric drive source for moving in the direction of separation, and a drive force transmission section that transmits one drive force of this drive source to the spot shot device, and the drive force transmission section is excited by the transmitted drive torque. It is constructed using a powder clutch that is approximately proportional to the current, and the amount of movement of the spot shot device is detected, and the excitation current of the powder clutch is controlled to be lowered as the spot shot device approaches a scheduled position according to the detection output. A spot shot drive device comprising: a movement detection control section; and a contact detection control section that detects that the spot shot device has come into contact with a subject and cuts off a power supply path of the drive source based on the detection.